KEY FULL — Listening 5 Homework (đáp án đầy đủ)

Bob: Hi Julia.

Julia: Hi Bob. Thought about the science project yet?

Bob: Which one? The presentations are scheduled for next month.

Julia: The experiment that you and I are working on to demonstrate density, buoyancy, and the compression of gases.

Bob: That'll be complicated.

Julia: Well, it's not supposed to be. It'll be part of the Making Science Simple series that's being showcased next year. And we have to be ready to demonstrate by the end of next week.

Bob: Oh, well, simple you say.

Julia: Yes, not just the concept but the materials too. We have to use cheap, readily available, common items. Expensive lab equipment is out of the question!

Bob: I remember something about using recycled or throw-away items if possible. Anything portable that we can bring into the lab.

Julia: That's right.

Bob: Well, any ideas for the project?

Julia: What about the classic Cartesian diver?

Bob: Is that the same as a Cartesian devil? The invention named after the famous French physicist - René Descartes?

Julia: Yes, a long time ago, superstitious people labeled it that because they couldn't comprehend the scientific principles it demonstrated. They thought it was black magic.

Bob: How shall we do it?

Julia: By keeping it as simple, transparent, and economical as possible.

Bob: So, to start with?

Julia: Open your pencil case and let's have a look. Mmm, you haven't got any.

Bob: Any what?

Julia: Paper clips.

Bob: Oh, there are lots of them in the bottom of my bag. They slip off my papers and collect in the bottom. Look, here's half a dozen.

Julia: But they're all big metal ones. I want little ones - small, vinyl-covered multi-colored ones.

Bob: Oh, I've got one or two of them too.

Julia: Great. And if we look around, especially on the floor, we're bound to find a few more. See? Here.

Bob: What else do we need?

Julia: A small rubber band.

Bob: Well, I've got one of those in my pocket.

Julia: No, not that kind. Let's go and ask Tara.

Bob: Why?

Julia: Those really small coloured bands for making ponytails are ideal.

Bob: Hey, Tara?

Tara: Yes?

Julia: Have you got any spare rubber bands like the ones you fasten your hair with?

Tara: Oh, heaps, a whole packet full - help yourselves.

Bob: Terrific. So far it hasn't cost us anything. What now?

Julia: Let's go and rummage through the recycling bins beside Joe's mini-market.

Bob: What for?

Julia: We want a 2-litre plastic soft drink bottle with a lid.

Bob: Hey, I draw the line at sorting through other people's rubbish, and we're also not likely to find one with a lid.

Julia: Well, go into the store and buy 2 litres of soft drinks.

Bob: What flavour?

Julia: It doesn't matter what kind of drink you get, just make sure it comes in a clear P.E.T. bottle.

Bob: Where are you going?

Julia: To the cafeteria behind the Resource Centre.

Bob: What for?

Julia: I'm after some straws.

Bob: I can get them from the shop when I buy the drink.

Julia: No, I've seen there. They're the waxed paper ones. We need clear plastic and I know they've got them in the cafeteria. I'll also see if I can get a tall plastic cup from there.

Bob: Good luck. Meet you back here in 5 minutes.

Julia: Maybe longer because I want to go over to my locker and get a wire coat hanger.

Bob: Right. Have we got everything now?

Julia: I think so. I've got extras of most things. So don't worry if this doesn't work the first time.

Bob: Okay. Assembly. Step 1.

Julia: Take a straw and fold it in two. No, not like that. These plastic ones are quite hard to fold. Try pinching it in the middle, that should make it easier to bend. You may even have to bite it but not too hard. You want a sharp crease but you don't want to break it.

Bob: How's this?

Julia: Good. Now, second step. Wrap a rubber band several times around the ends to hold them together.

Bob: Then?

Julia: Add weight to the diver.

Bob: So, this straw is the diver?

Julia: Yes. See how I'm pulling the outside end of a paper clip out a bit. Now, hook the part I bent out into the rubber band that's holding the straw together. No, not that way, it'll fall off. That's right, turn it over. Now, hook two or three more paper clips on. It's hard to say how many we'll need. The idea is to get the diver to be almost all the way submerged, but not quite. We can put it in this tall cup of water to test it.

Bob: Hmm. What do you think? Too buoyant? Add another paper clip?

Julia: I think so. Okay, onto the next step. Have you got the empty bottle?

Bob: Not quite.

Julia: What do you mean?

Bob: Well, it's not quite empty.

Julia: Pour some into this cup for later. Good. Now fill the bottle with water all the way to the top and we'll gently lower the diver in. Great. Now put the cap back on.

Bob: And then?

Julia: The final step is the demonstration of our experiment. You will see that when I squeeze the bottle, the diver sinks, and when I let it go, the diver rises.

Bob: When you squeeze, the air bubble trapped in the straw compresses and the water rushes in making it heavier, so it sinks. And the reverse happens when you release the bottle. What's the coat hanger for?

Julia: Oh, that? If our experiment didn't work the first time and our diver stayed on the bottom, we'd have had to fish it out with a piece of wire or a hook of some kind. It's best to be prepared.

Clare: Hi, Grant. What sort of competition do you think we should organize?

Grant: Well, Clare, the Open Day Committee was pretty clear on that. It must be something with youth appeal.

Clare: That makes sense. After all, most of the visitors will have just left high school.

Grant: Yeah, so I was thinking technology.

Clare: Do you mean something which uses the latest technology, like an iPod?

Grant: Something like that but a bit more expensive maybe.

Clare: What about the latest iPhone? I'm saving up for one right now.

Grant: Let's make it an iPad. I wish I'd had a tablet computer when I started university.

Clare: Yeah, that's a great idea. That should get a lot of our younger visitors interested. Right. Let's go with that then.

Fine. We could go into town now and buy it. I saw great deals advertised at the Rick Smith store.

Grant: Oh, I don't think we'll have to worry about that. A university purchase order will probably be arranged through the Resources and Supplies Section.

Clare: Well, that's settled then. What about the competition? Is it going to be a game of skill or a guessing game or something else?

I don't think it should be anything too hard or anything that will make the visitors look silly. Some of them have such fragile egos.

Grant: True. So something that anyone can do. Nothing competitive, skill or intelligence involved?

Clare: That's right. But the main thing is that the contestants have a lot of fun.

It's a series where in every episode the main characters step through a portal into another world or another era.

Grant: What's a portal?

Clare: It's like a gateway or entrance to something.

Grant: Okay, I get it. They are stepping into the new world of tertiary learning. How do we get people to step through this portal, then what?

Clare: They get their photo taken stepping through the portal.

Well, firstly, they have to make their way to the portal photo booth on campus.

Grant: And they'll have to write down their details. Just name and email address should do.

Clare: Then, after say the thirtieth of July, people can visit the university Facebook page and vote for their favourite photo.

The most popular photo as of 5pm on the tenth of August will collect the iPad.

Grant: But there's just one more thing. How do we get hold of a portal?

Clare: I was thinking graduates of the Engineering Department could construct it as part of their contribution to Open Day.

Grant: Great.

Section 3. You will hear a student called John talking to a professor about a design competition he is entering. First, you have some time to look at questions 21 to 25. Now listen carefully and answer questions 21 to 25.

John: Hello Professor.

I'm John Wishart.

I'm working on my entry for the Global Design Competition.

My tutor said you might be able to help me with it.

Professor: Ah yes, I got a copy of your drawings.

Come in and tell me about it.

What sort of competition is it?

John: Well, it's an international design competition and we have to come up with a new design for a

typical domestic kitchen appliance.

Professor: I see.

And are there any special conditions?

Does it have to save energy, for example?

John: Actually, that was the focus in last year's competition.

This year's different.

We have to adopt an innovative approach to existing technology, using it in a way that hasn't been

thought of before.

Professor: I see.

That sounds tricky.

And what kitchen appliance have you chosen?

John: Well, I decided to choose the dishwasher.

Professor: Interesting.

What made you choose that?

John: Well, they're an everyday kitchen appliance in most Australian houses, but they're all pretty boring and almost identical

to each other.

I think some people will be prepared to pay a little extra for something that looks different.

Professor: That's a nice idea.

I see you've called your design the rock pool.

Why is that?

John: Basically because it looks like the rock pools you find on a beach.

The top is made of glass so that you can look down into it.

And there's a stone at the bottom.

Professor: Is that just for decoration?

John: Actually, it does have a function.

Instead of pushing a button, you turn the stone.

Professor: So it's really just another way of starting the dishwasher?

John: That's right.

Professor: It's a really nice design, but what makes it innovative?

John: Well, I decided to make a dishwasher that uses carbon dioxide.

Professor: In place of water and detergent?

How will you manage that?

John: The idea is to pressurise the carbon dioxide so that it becomes a liquid.

The fluid is then released into the dishwasher where it cleans the dishes all by itself.

Professor: Sounds like a brilliant idea.

Your system will totally do away with the need for strong detergents.

So what happens once the dishes are clean?

John: Well, to allow them to dry, the liquid carbon dioxide and the waste materials all go to an

area called the holding chamber.

That's where the liquid is depressurised and so it reverts to a gas.

Then the oil and grease are separated out and sent to the waste system.

Professor: It sounds like you've thought it all out very thoroughly.

So what happens to the carbon dioxide once the process is complete?

Not wasted, I hope.

John: Actually, that's where the real savings are made.

The carbon dioxide is sent back to the cylinder and can be used again and again.

Professor: What a terrific idea.

Do you think it will ever be built?

John: Probably not, but that's OK.

Professor: Well, I'm sure a lot of positive things will come out of your design.

Before you hear the rest of the discussion, you have some time to look at questions 26 to 30. Now listen and answer questions 26 to 30.

Professor: Now you seem to have thought about everything, so what exactly did you need me to help you

with?

John: Well, my design has made it to the final stage of the competition and in a few months

time I have to give a presentation and that's the part I was hoping you could help me

with.

Professor: Right, well that should be easy enough.

What have you managed to do so far?

John: Well, I've got detailed drawings to show how it will work and I've also written a 500 word

paper on it.

Professor: I see.

Well, if you want to stand a good chance of winning, you really need a model of the

machine.

John: Yes, I thought I might, but I'm having a few problems.

Professor: What's the main difficulty so far?

Let me guess, is it the materials?

John: Yes, I want it to look professional, but everything that's top quality is also very expensive.

Professor: Look, projects like this are very important to us.

They really help lift our profile.

So why don't you talk to the university about a grant?

I can help you fill out the application forms if you like.

John: That would be great.

Professor: You'd better show me this paper you've written as well.

For a global competition such as this, you need to make sure the technical details you've given are

accurate and thorough.

John: Oh, that would be a great help.

Professor: Is there anything else I can do?

John: Well, I'm really nervous.

That is the end of Section 3. You now have half a minute to check your answers. Now turn to Section 4.